from rest_framework import serializers

from django.urls import reverse

from misago.api.serializers import MutableFields
from misago.core.utils import format_plaintext_for_html

from .models import Category


__all__ = [
    'CategorySerializer',
    'BasicCategorySerializer',
    'CategoryWithPosterSerializer',
]


def last_activity_detail(f):
    """util for serializing last activity details"""

    def decorator(self, obj):
        if not obj.last_thread_id:
            return None

        acl = self.get_acl(obj)
        tested_acls = (acl.get('can_see'), acl.get('can_browse'), acl.get('can_see_all_threads'), )

        if not all(tested_acls):
            return None

        return f(self, obj)

    return decorator


class CategorySerializer(serializers.ModelSerializer, MutableFields):
    parent = serializers.PrimaryKeyRelatedField(read_only=True)
    description = serializers.SerializerMethodField()
    is_read = serializers.SerializerMethodField()
    subcategories = serializers.SerializerMethodField()
    acl = serializers.SerializerMethodField()

    url = serializers.SerializerMethodField()

    class Meta:
        model = Category
        fields = [
            'id',
            'parent',
            'name',
            'description',
            'is_closed',
            'threads',
            'posts',
            'last_post_on',
            'last_thread_title',
            'last_poster',
            'last_poster_name',
            'css_class',
            'is_read',
            'subcategories',
            'acl',
            'level',
            'lft',
            'rght',
            'url',
        ]

    def get_description(self, obj):
        if obj.description:
            return {
                'plain': obj.description,
                'html': format_plaintext_for_html(obj.description),
            }
        return None

    def get_is_read(self, obj):
        try:
            return obj.is_read
        except AttributeError:
            return None

    def get_subcategories(self, obj):
        try:
            return CategorySerializer(obj.subcategories, many=True).data
        except AttributeError:
            return []

    def get_acl(self, obj):
        try:
            return obj.acl
        except AttributeError:
            return {}

    @last_activity_detail
    def get_last_poster(self, obj):
        if obj.last_poster_id:
            return {
                'id': obj.last_poster_id,
                'avatars': obj.last_poster.avatars,
                'url': reverse(
                    'misago:user', kwargs={
                        'slug': obj.last_poster_slug,
                        'pk': obj.last_poster_id,
                    }
                )
            }
        return None

    def get_url(self, obj):
        return {
            'index': obj.get_absolute_url(),
            'last_thread': self.get_last_thread_url(obj),
            'last_thread_new': self.get_last_thread_new_url(obj),
            'last_post': self.get_last_post_url(obj),
        }

    @last_activity_detail
    def get_last_thread_url(self, obj):
        return obj.get_last_thread_url()

    @last_activity_detail
    def get_last_thread_new_url(self, obj):
        return obj.get_last_thread_new_url()

    @last_activity_detail
    def get_last_post_url(self, obj):
        return obj.get_last_post_url()


class CategoryWithPosterSerializer(CategorySerializer):
    last_poster = serializers.SerializerMethodField()

    def get_subcategories(self, obj):
        try:
            return CategoryWithPosterSerializer(obj.subcategories, many=True).data
        except AttributeError:
            return []

CategoryWithPosterSerializer = CategoryWithPosterSerializer.extend_fields('last_poster')


BasicCategorySerializer = CategorySerializer.subset_fields(
    'id', 'parent', 'name', 'description', 'is_closed', 'css_class',
    'level', 'lft', 'rght', 'url'
)
